package com.atguigu.gulimall.cart.interceptor;

import com.atguigu.common.constant.AuthServerConstant;
import com.atguigu.common.constant.CartConstant;
import com.atguigu.common.vo.MemberRespVo;
import com.atguigu.gulimall.cart.vo.UserInfoTo;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.util.UUID;

/**
 * 在执行目标方法之前，写一个拦截器，判断用户登录的状态。
 * 并封装传递给Controller目标请求
 */
@Component
public class CartInterceptor implements HandlerInterceptor {

    public static ThreadLocal<UserInfoTo> threadLocal = new ThreadLocal<>();

    /**
     * 在目标方法执行之前进行拦截： return true是放行,return false是不放行
     * @param request
     * @param response
     * @param handler
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        UserInfoTo userInfoTo = new UserInfoTo();
        HttpSession session = request.getSession();
        MemberRespVo member = (MemberRespVo)session.getAttribute(AuthServerConstant.LOGIN_USER);

        if(member != null){     //说明用户没登录
            userInfoTo.setUserId(member.getId());
        }
        Cookie[] cookies = request.getCookies();
        if(cookies != null && cookies.length > 0){
            for (Cookie cookie : cookies) {
                String name = cookie.getName();
                if(CartConstant.TEMP_USER_COOKIE_NAME.equals(name)){
                    userInfoTo.setUserKey(cookie.getValue());
                    userInfoTo.setTempUser(true);//有临时用户我们才在浏览器存入新的cookie，否则的话我们每次都会给浏览器设置新的过期时间
                }
            }
        }
        //不论是否登录只要临时用户为空我们都在里面放入临时用户身份的cookie
        if(StringUtils.isEmpty(userInfoTo.getUserKey())){
            String uuid = UUID.randomUUID().toString();
            userInfoTo.setUserKey(uuid);
        }
        threadLocal.set(userInfoTo);
        return true;
    }

    /**
     * 在业务执行之后，需要给浏览器保存这个临时用户的user-key
     * @param request
     * @param response
     * @param handler
     * @param modelAndView
     * @throws Exception
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        UserInfoTo userInfoTo = threadLocal.get();
        if(!userInfoTo.isTempUser()){
            Cookie cookie = new Cookie(CartConstant.TEMP_USER_COOKIE_NAME, userInfoTo.getUserKey());
            cookie.setDomain("gulimall.com");
            cookie.setMaxAge(CartConstant.TEMP_USER_COOKIE_TIMEOUT);
            response.addCookie(cookie);
        }

    }
}
